Means for securing buckets in turbines.



PATENTED JAN 15, 1907.

. c. B. LITTLE;

MEANS FOR SECURING BUGKBTS IIN TURBINES.

APPLICATION IILED JULY 19, 1905.

2 SHEETSSHEBT 1..

v I nvntor; Clarence El Littl IIIIIII'III l lll'ull-llllllul [I'lil ll a ttiy.

.vwtnessesz UNITED STATES PATENT oFrIcE.

- CLARENCE E. LITTLE, OF LYNN, MASSACHUSET' S, ASSIGNOR TO GENERA ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FOR SECURING BUCKETS IN TURBINES.

No. seizes.

Specification of Letters Patent,

Patented Jan. 15, 1907.

Applicati n filed July 19,1905. Serial No. 270,432.

To all whom it may concern):

Be it known that I, CLARENCE E. LITTLE, a citlzen of the United States, residing at Lynn,

county of Essex, State of Massachusetts, have dered more certain, and the cost of manufac v ture reduced.

In the accompanying drawings, which illustrate one embodiment of my invention, Figure .1 is an axial section of a turbine with the governor-casing in elevation, the section being taken on line -1 ,1 of Fig. 2. Fig.2 is a cross-section of the same with certain of the parts in elevation. Fig.3 is a perspective view of one of the attaching-bolts, and Fig. 4 shows a detail sectionwherein three rows of intermediates are provided.

The casing 1 is preferably made as a single casting to eliminate the joints as far as possible. It can, however, be made in two or more parts, if desired. When the latterflarrangement is followed, the parts will ordi-.

narily be fastened together once for all, since ,the wheel and the intermediatevbuckets are made removable by a relative axial movement of the wheel and casing. The righthand end 2, or the bottom, in the case of a vertical-shaft machine, is preferably, but not 4 necessarily, formed integral with the casing, while'the left-hand end or head 3, or the top, in case of a vertical-shaft machine,'is ad e removable and is secured in place by suitable means, such as bolts. At the points of entrance to the casing the shaft 4 or hub 5 of the bucket-wheel is provided with p ackings 6 and 7 to prevent theescape of'inotive fluid.

The wheel is provided with two or more rows of buckets 8' to produce rotation when subjected to elastic fluid under velocity from the nozzle or other fluid-discharging device 9. The nozzle is preferably of the expanding type and converts the pressure of the fluid Wholly or largely into velocity before :discharging it to the wheel. The nozzle is usually of. the sectionalized type, comprising a number'of closely-associated passages which discharge the motive fluid 'in the form of a solid column or jet. Between each two rows of wheel-buckets are more or less complete rows of intermediate buckets 10, which serve to reverse the motive fluid as it flows through one row of buckets after the other and has its velocity abstracted by successive operations. These intermediate buckets are provided with sharp edges and are closely associated, so that the motive fluid is discharged as nearly as possible in a solid column. When these intermediate buckets cover less than the entire circumference of the wheel, blank walls 11 are provided, which extend from one end I of the bucket support or ring to the other or from one set of buckets to the other, as the case may be These blank walls are finished on the sides and are separated from the wheel buckets by axial clearances,which are substantially the same as the clearances between the wheel and intermediate buckets. When the parts are thus arranged, the walls assist in reducing rotation losses by preventin the fan-like action of the idle moving buc ets. The right-hand wall of the casing and also the head are shaped to conform to the wheel to further reduce rotation losses.

The interior of the wheel-casing is provided with a shoulder 12, that may be integral with or attached to the casing. Abutting this shoulder is a ring carrying the intermediate buckets when the latter extend entirely around the wheel and the intermediates and blank walls when the former extend only partially around the wheel. This ring may be made in two or more pieces. The buckets may be cut or cast therein. The periphery of the ring makes a working fit with the casing, or some part thereof, which serves to center it and also to hold it in place. The entire inner surface of the casin need not be finished on account of expense, int should at least be finished in spots or providedwith projections which are finished. The main thing is tocenter the rings properly, so that the alinement of the buckets will'be pre served at all times, and to guide them when being inserted in place; However the inside of the casing is finished the rings should be arranged to slip freely into the casing one after the other. Adjacent to the ring above referred to is a. follower 13, comprising a ring which may be made in one or more pieces.

The periphery is finished and engages some part or partsof the casing, which serve to cener it. The opposite sides of the ring are carefully finished, so that it serves as a spacing device for separating one intermediatebucket rin from the other. In addition to this the fo lower-ring serves to decrease the rotation losses of the rapidly-revolvingwheel,

and it also cuts down the free space in which the exhaust flaidpan collect. On the side'of also increase towardr-the exhaust.

- make a working fit with certain surfaces within-the casing in order to be readily movable by an axial movement of the casing and wheel relatively to each'other. In order to prevent these parts from moving circumferentially with respect to the casing when the machine is in operation, one or more keys 16, Fig. 2, or equivalent devices are employed, which are common to said parts. This arrangement will permit the parts to be rather loosely fitted without permitting the relation to be disturbed. In order to clamp the parts in place and at the same time permit of the head bein removed without disturbing them, individua clamping devices 17 are provided, of whichas many are provided as are necessary. .These retaining devices comprise a clamping-piece 18., which engages the first ring, and also a cylindrical shoulder 19,formed on or attached to the wheel-casing. Extending through the clamp is a bolt which enters the shoulder and is accessible from the high-pressure end of the machine when the head is removed. a T he bolt exerts axial pressure on the parts and is prevented from turning by a lock-washer 20, which is provided with lips 21, that engage the head of the bolt. The washer itself is prevented from turning by the projection 22, that engages a flattened portion of the cylindrical clamping-piece 18. The clamping-pieces fit into a slight depression or orifice 23, formed in .the casing, and

by reason of the eccentricarrangement of the clamping-bolts are prevented from turning.

In assembling the parts the casing is moved up adjacent to .the wheel and the parts of the first intermediate-bucket ring placed around the wheel. Then the casing is moved along to engage the ring; The next step is to mount the follower in place and move the casing along to engage and hold it in place. The parts of the second ring are then placed around the wheel and'the casing moved along axially to engage it. The rings an'dfollower are then moved against the seat or shoulder on the casin and the clamps mounted in place. Final y the head 3 and attached parts are mounted in place.

In event of the rings being continuous they can be applied to the wheel before the succeeding'r'ows of buckets after the first are mounted in place. In this case the diameter of the-inner surface of the rings should be slightly greater than the diameter of the ortion or portions of the wheel over which t ey must slide, aswill be readily understood.

In Fig. 4 are shown three rings composed of intermediate buckets and blankwalls, and two followers situated between the adjacent rings. The number of'bucket-rings and followers can be increased ad libitum, since it in no way changes the principle of my invention.

In so far as the idea of. using rings, either complete or' segmental, is concerned the blank portions or walls between the buckets need not act as devices, for decreasing rotationlosses but I-consider advisable to use them. v

The invention is applicable toverticalshaft machinesand a so to multistage machines whetherthe shaft be vertical or hori zontal. i

The governor for controlling the speed of the turbine is mounted on the endof the a shaft and is inclosed by the casing 24;. Steam or other elastic fluid is admitted to the nozzle or nozzles from a suitable valve-chest 25. The exhaust from the wheel is discharged into a circular conduit 26, that is connected to a suitable point of exha'usts'uch, for example, as the atmosphere or a condenser.

In some instances the head may beprovided with one or more projections, movable or otherwise, which engage the adjacent ring, and thus hold the parts in pl ace. When such an arrangement is employed, the bolts retaining the cover will also serve to hold' the parts in place. It is the better practice to have one or more clamps which are movable 1 independently of the head to holdthe parts,

since by so doing the effects of 'errors in machine-work are reduced to a minimum.

In accordance with the provisions of the patent statutes I have described the ,principle of operation .of my invention, together with the apparatus which I now consider to represent the best embodiment thereof .but'

I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by-other'means,

What I claim as new, and desire"v to secure;

by Letters Patent of the United States, is' 1. 'An elastic-fluid turbine comprising a wheelhaving rows of peripheral buckets, a

casing, and fluid-admitting means, in combination with closely-associated intermediate buckets, a support therefor located between port,'a'. shoulder for positioning the interme- 3e. one of the rings, and one or more devices "ring between each .two intermediate-bucket vices for exerting pressure in an axial direction on the intermediate-bucket supports tion of a. wheel baving'rows of peripheral ingthe ends of the intermediate-bucket supdiate buckets within the casing, and a clamping device for the support wbichexerts pressure in an axial direction.

2. An elastic-fluid turbine comprising a wheel having rows of buckets thereon, a fluid-admitting means, and a casing, the wheel and casingbeing so arranged'that theycan be separated by an axialmovement, in E combination with closely-associated intermediate buckets arranged in segmental rows,- supports therefor located between the rows of wheel-buckets, blank walls connecting the opposite ends of thesegmental rowsof buckets, a follower or spacer between the rows of intermediate buckets, and one or more deandv the follower or's acer.

3, An elastic-flui turbine comprising a wheel having rows 'of buckets thereon, a fluid-admitting means, and a casing, in combination wit-litwo or more rows of closely-associated intermediate buckets having-sharp edges and arranged in rings, portions of which are blank, a follower between each two adjacent rings, an abutment receiving.

which exert apressure on the ringsand the follower to seat the par-ts againstthe abut ment. Y 1

4. An elastic-fluid turbine corn rising .a wheel having rows of buckets t ereon, a fiuid-admittingmeans, and a casing having ashoulder, in combination with intermediate bucketsnarranged in the form of rings which are slipped axially into the casing, a' ollo'w'errings, means which engages one of the rings and said shoulder'for clamping-the bucket and followerrings in place, and a key for preventing the bucket and follower rings from turning.

5. "In an elastic-fiuid turbine, the combinabuckets thereon, a casing having an internal shoulder, an intermediate-bucket ring which rests on the shoulder, a second intermediatebucket ring, a follower between said rings which se arates them by a fixed distance, a second s ioulder formed on the casing, and clam ing devices which engage the-second shou der and also a ring for holding the intermediate buckets in place.

6. In an elastic-fluid turbine, the combination of a wheel having rows of peripheral buckets thereon, a casing having an internal shoulder, intermediate-bucket rings which are restrained from axial movement by the shoulder, afollower between the rings, clamping devices. located within the casing which exert axial pressure on the rings and 'fol lower, a nozzle or other device admitting fluid to the buckets,and a head for the casing which carries the nozzle andfwhen removed exposes the clamping devices. I

7. In an elastic-fluid turbine, the combination of a casing, a wheel having rows of peripheral buckets, intermedi-ate-bucket;carry ing rings located'between the rowsof'wheel buckets, a follower betweenadjacent bucketrin s, shoulders-formed onthe'oasing, one of which acts as'an abutment, and clamping devices which engage the other shoulder and also one'of the rin S; S. In anelasticiuid turbine, the combination of a casing, a wheel having rows of peripheral buckets, intermediate-bucket-carrying rings located, between the rows of wheel-' buckets, whichare' slipped into the casing one after the'other, blank walls on the rings which reduce the fan-like action of the idlewheel buckets, a follower which surrounds the wheel and spaces the adjacent rings and is slipped into t e casing between the rings, and means for clamping the rings and followers in place.

In witness whereof I have hereunto set my hand this 7th da of Jul 1905.

- LARE CE E. LITTLE.

\Nitnesses:

JOHN A. MoMANUs, Jr., FRED L. HITCHCOCK. 

